The present invention relates to a vibration damping device for stopping squeaks of a disc brake by actively damping vibrations of a disc rotor (hereinafter referred to simply as "rotor"), which is a leading cause of squeaks of the disk brake.
Unexamined Japanese Patent Publications 4-54324 and 4-54325 disclose one type of active vibration damping mechanisms for suppressing squeaks of a disc brake. The mechanisms have a piezoelectric element for detecting vibrations of a brake pad (hereinafter simply referred to as "pad") and adapted to damp vibrations of the pad to suppress squeaks in response its detection signals.
A leading cause of squeaks of a disc brake is the vibration of the rotor. But as disclosed in the above publications, conventional vibration damping mechanisms are adapted to damp vibrations of a pad to indirectly suppress vibrations of the rotor. None of the prior are mechanisms can directly damp the vibration of the rotor. Thus, they cannot effectively reduce squeaks of disc brakes.
An object of the present invention is to solve the above no problem.